Most antimicrobial products contain chemically based agents that can kill or slow down the growth of microorganisms, for instance, β-lactams, cephalosporins, sulfonamides, quaternary ammonium compounds, triclosan, or metal ions based nanoparticles. With the broad application and abuse of such chemical biocides, there is a rising global threat of antimicrobial resistance to conventional treatments. Antimicrobial biomimetic surfaces based on cicada or dragonfly wings have been reported. These biomimetic surfaces comprising a plurality of nanospikes, such as disclosed in WO 2015/031956, show a great potential for antibacterial or other antimicrobial applications. Unlike when antibiotics or other chemical compounds are used to kill bacteria, the bactericidal effects of such nanomaterials come from the mechanical response of the nanostructures which kill microorganisms on contact. The antimicrobial effects come from the physical disruptions of cell walls induced by surface texturing and are independent on the surface chemical functionality; therefore such nanomaterials could reduce the risk of antimicrobial resistance or could be used in applications where e.g. bacteria have already developed resistance to traditional antibiotics.
There is however still room within the art for improving such antimicrobial surfaces in order to extend their range of potential applications and/or their biocidal properties.